Anorexia Nervosa (AN) is a psychobiological disorder possessing significant morbidity and mortality. Cardiovascular (CV) dysfunction accounts for a large proportion of the complications and includes rhythm disturbances, alterations in cardiac chamber size and contractility, and impaired exercise performance. Because of the tendency of AN patients to consume calories as protein to the exclusion of other sources, AN is not analogous to starvation models of protein-calorie malnutrition. AN patients may also display the poorly understood tendency to develop their most marked CV dysfunction during the period of greatest weight gain during their recovery. This proposal examines the hypothesis that clinical or subclinical CV dysfunction of AN reaches its nadir during the phase of rapid weight gain and that CV recovery lags behind weight restoration. To test the above hypothesis, this study will incorporate complete non-invasive cardiac evaluation of patients with severe AN at the time of their hospitalization (usually at or very close to the nadir of their weight). The evaluation will include: electrocardiogram, M-mode, and 2 dimensional echocardiogram, 24 hour ambulatory electrocardiography, and exercise stress testing including radionuclide ventriculography. The subjects will be hospitalized for a treatment program including a weight restoration plan based on an operant conditioning paradigm, thrice weekly individual re-educative psychotherapy and weekly family therapy. Unique to this study, the subjects will undergo repeat measurement of CV performance at several points in their recovery (after regaining 25% and 75% of their calculated weight deficit) and at one year following initial hospitalization. If our hypothesis is correct, the most evidence of CV dysfunction will be seen in the period of rapid weight gain whether or not clinical manifestations appear. The expected findings should aid clinicians in anticipation of CV problems in the management of patients with AN.